More TL questions

Question 1

HOw do you calculate gas remaining in Nitrous tank?

Answer 1

At the initial point when all liquid gas has been used up, the pressure will still read ~745 psig but only ~250 L will remain, or 253.4 to be exact. Then, the pressure will fall rapidly as the gaseous form of N2O is used up. At this point, the tank is approximately 16% full (253 L / 1590 L). A tank showing a pressure of 400 psig would contain ((400 psig / 745 psig) * 253 L) = 136 L of remaining N2O. A pressure of ~350 psig corresponds to ~120 L of remaining N2O.

Question 2

What phsyiological cahnges are seen with anemia?

Answer 2

An increase in cardiac output, the rightward shift in the oxyhemoglobin dissociation curve, decreased blood viscosity, and blood flow redistribution to vital organs all work to do this.

Question 3

What are th 6 parts of the revised cardiac index?

Answer 3

Revised Cardiac Risk Index Variables:

1) History of ischemic heart disease
2) History of congestive heart failure
3) History of cerebrovascular disease
4) Insulin therapy for diabetes
5) Preoperative serum creatinine > 2.0 mg/dL
6) High-risk type of surgery

Question 4

At which level of spinal cord injury does the risk for autonomic dysreflexia begin to increase significantly?

Answer 4

T6
Autonomic dysreflexia (AD), also called autonomic hyperreflexia, occurs when a noxious stimulus such as pain or organ distention causes a signal to be transmitted to the dorsal root of the spinal cord.  An increase in sympathetic outflow and vasoconstriction occurs below the level of the lesion.  Without a spinal cord injury, inhibitory impulses from the brain modulate the sympathetic outflow.  With a lesion at T6 or above, this inhibition is blocked, and therefore the sympathetic outflow goes unchecked, causing the hypertension, diaphoresis, headache, and arrhythmias characteristic of autonomic dysreflexia.  AD has been known to occur in patients with a lesion as low as T10, though T6 and above is the highest risk.

Question 5

Can yuo give sux to peopel with GBS?

Answer 5

NO, don’t
Administration of succinylcholine is contraindicated (A) in patients with GBS. When demyelination occurs muscle fibers receive less neural input. With less input the muscle begins to synthesize immature acetylcholine receptors (AChR) as a compensatory mechanism. Immature AChR have an epsilon subunit as opposed to a gamma subunit. These receptors remain open longer and allow a larger efflux of potassium from the muscle cells. When succinylcholine is administrated to a patient with GBS it is associated with significant rises in serum potassium which can precipitate a hyperkalemic cardiac arrest.

Question 6

lung function prone vs supine

Answer 6

In an optimally positioned patient undergoing positive pressure ventilation, the prone position is a more effective position for lung function. Pulmonary changes when compared to the supine position include increased ERV and FRC, improved pulmonary compliance, decreased atelectasis, improved V/Q matching, and decreases lung stress and strain overall.

Question 7

Most common cause of periopoerative mortality in obese patietns

Answer 7

DVT
Morbid obesity has widespread systemic effects. Obesity is an independent risk factor for heart disease and hypertension, obstructive sleep apnea, stroke, hyperlipidemia, osteoarthritis, and diabetes are more common as well. The leading cause of perioperative mortality in the morbidly obese is deep vein thrombosis with subsequent pulmonary embolism. Deep vein thrombosis prophylaxis should be considered, especially in longer procedures.

Question 8

complete vs partial injury to bilateral RLN injury

Answer 8

Partial injury= complete obstruction
Complete injury= partial obstruction

The RLN provides the only abductors of the vocal cords which are very sensitive to injury/compression. Thus, partial bilateral recurrent laryngeal nerve injury results in complete obstruction (abductors affected most, unopposed adduction of vocal cords) and is an airway emergency. Complete bilateral RLN injury results in the vocal cords being in a paramedian position causing aphonia and aspiration risk.

Question 9

What is phenoxybenzamine

Answer 9

Phenoxybenzamine is a non-specific , irreversible alpha blocker with a half-life of approximately 24 hours. Its alpha blocking properties have made it an attractive perioperative therapy in the setting of catecholamine secreting tumors that cause vasoconstriction and hypertension.
Blockade of alpha-1 and alpha-2 leads to smooth muscle relaxation in arterioles and venous capacitance vessels. Orthostatic hypotension and reflex tachycardia, especially in the setting of hypovolemia, are potential side effects of phenoxybenzamine related vasodilation.

Question 10

WHat are the results of phenoxybenzamine?

Answer 10

Phenoxybenzamine is a non-specific alpha blocker, thus blockade of alpha-2 receptors can cause increased heart rate and blood pressure.

Question 11

What is fetal acidemia

Answer 11

Fetal acidosis may be assessed through fetal scalp blood gas analysis. Lactate or pH levels that fall in the range for fetal acidemia may prompt obstetricians to consider transitioning to emergent operative delivery, especially in the setting of non-reassuring fetal heart monitoring. Fetal acidemia is defined as pH < 7.21 or lactate > 4.8 mmol/L.

Question 12

Most important factors relating to spread of spinal block

Answer 12

Drug dosage (milligrams of drug delivered), baricity, and patient position are the most important factors determining the level of spinal blockade.

Drug colume is less importnat–tends to be very important in epidural spread

Question 13

What are common renal changes seen in anesthesia?

Answer 13

The sympathetic nervous system provides baseline vascular tone in the kidney and when activated causes vasoconstriction that can decrease renal blood flow.

TrueLearn Insight : Inhaled anesthetics cause a transient reversible depression in renal function. GFR, renal blood flow, urine output, and urinary excretion of sodium are decreased

Question 14

WHat is ANP?

Answer 14

Atrial natriuretic peptide (ANP) is released from the atria in response to high filling pressures. ANP is a vasodilator of the afferent arterioles and a vasoconstrictor of the efferent arterioles, and will, therefore, increase blood flow to the kidneys when released in response to stretching of the atria.

Question 15

What slows down indcution…think shunt adn solubiilty

Answer 15

R-> L shunt and less soluble agents
Factors that result in a slowing of an inhalational induction include the presence of a right-to-left intracardiac shunt, as well as the use of a less soluble volatile anesthetic agent. (like des or sevo)

Question 16

Cyanotic lesions

Answer 16

A mnemonic that can be used to remember the cyanotic heart lesions which are associated with right-to-left intracardiac shunts is:
1 Combined Vessel - Persistent truncus arteriosus
2 Vessels Switched - Transposition of the great vessels
3 Leaflet Valve - Tricuspid Atresia
4 Abnormalities - Tetralogy of Fallot
5 Words in the Name - Total anomalous pulmonary venous return

Question 17

Needle stick HIV prophylaxis

Answer 17

No post-exposure prophylaxis is necessary for exposure to a patient with unknown HIV status who is at low risk for HIV. Two drug prophylaxis is recommended when there is exposure to a known HIV patient and the exposure is superficial or exposure occurs with a solid needle. Three drug prophylaxis is recommended in severe exposure when the patient is known to have HIV or AIDS.

Question 18

How does furosemide help in CHF?

Answer 18

Congestive heart failure is a condition in which the heart fails to provide adequate forward output resulting in systemic venous congestion. Furosemide provides the greatest benefit acutely by reducing systemic venous resistance by increasing venous capacitance to assist in mobilization of fluid.
Furosemide increases venous capacitance which decreases left ventricular end diastolic volume and pressure as well as myocardial wall stress or afterload. A reduction in wall stress will also reduce myocardial oxygen consumption while improving the pumping of the ventricle. This occurs secondary to the venous capacitance effect

Question 19

MOA furosemide

Answer 19

furosemide exerts its diuretic effect by inhibiting the reabsorption of sodium and chloride, primarily in the medullary portions of the ascending limb of the loop of Henle.

Question 20

most effecint fresh gas flow mapleson

Answer 20

A circuits are more efficient during spontaneous ventilation, while Mapleson D circuits are most efficient during controlled ventilation. Overall, the Mapleson D arrangement is the most efficient in both controlled and spontaneous ventilation.

TrueLearn Insight : “ASk for a CD.” Mapleson A = most efficient with Spontaneous ventilation. In Controlled ventilation, Mapleson D is most efficient.

Question 21

What is the MOA of terbutaline?

Answer 21

Terbutaline can be used to slow or halt premature labor via its selective ß2-agonism, which results in uterine relaxation. Like all catecholaminergic agents, it exhibits dose-dependent interaction with other catecholaminergic receptors. Further, this interaction varies from patient to patient.

Question 22

Example fo beta-1 agonist

Answer 22

An example of a selective β1-agonist is dobutamine, used to improve cardiac output in heart failure and cardiogenic shock.

Question 23

What si the adductor canal block?

Answer 23

The adductor canal block, a variant of a saphenous block, is often used as an analgesic adjunct for knee surgery. Studies have shown that pain relief provided by adductor canal block is non-inferior to femoral nerve block. Additionally, these blocks were found to have less risk for falls. Though the saphenous nerve is purely sensory, an adductor canal block often affects the nerve to the vastus medialis because of its location within the adductor canal. Motor weakness may occur and patients should be closely monitored as they begin to ambulate.

Question 24

Pain on injection (list)

Answer 24

Pain on injection is common with many medications including propofol, etomidate, diazepam, methohexital, and rocuronium. In general, it has not been shown to occur on injection with opioids, ketamine, midazolam, fospropofol, or dexmedetomidine.

Question 25

kids with mitochonrial defects

Answer 25

Patients with mitochondrial myopathies should have a thorough preoperative evaluation aimed at minimizing stress from anxiety, hypothermia, hypoglycemia, hypovolemia, and acidosis. Anesthetic agents that are safe to use in these patients include midazolam, short-acting opioids, and alpha-2 agonists. Ketamine and low-dose nondepolarizing muscle relaxants are also likely safe. Volatile anesthetics, propofol, and depolarizing muscle relaxants should be used with caution.

Question 26

Risk factors for difficult intubation in obese

Answer 26

Obesity and BMI themselves are not risk factors for difficult intubation. Three factors obtained by history or physical exam that correlate with difficult intubations in obese patients include increased neck circumference, Mallampati class III or IV airway, and the presence of obstructive sleep apnea. In general, increased age, male sex, TMJ pathology, and abnormal upper teeth also correlate with difficult intubations.

Question 27

What are the indications for hyperbaric oxygen chamber in a CO case?

Answer 27

Commonly used guidelines for the application of HBO therapy in CO poisoning include the following:

1. A history of neurologic impairment (including dizziness, loss of consciousness)
2. Evidence of cardiac abnormalities (ischemia, arrhythmias, ventricular failure)
3. A HbCO level that has been greater than 25%

Question 28

Anesthetic considerations in RA patients

Answer 28

Anesthetic Considerations for Rheumatoid Arthritis:
Airway: Limited TMJ movement, narrow glottic opening
Cervical spine: Atlantoaxial instability
Cardiac: Pericarditis, cardiac tamponade
Eyes: Sjo¨gren’s syndrome
Gastrointestinal: Gastric ulcers secondary to ASA/ steroids
Pulmonary: Diffuse interstitial fibrosis
Renal: Renal insufficiency secondary to NSAIDs

Question 29

REtrobulbar complications

Answer 29

Retrobulbar hemorrhage is the most common significant complication following retrobulbar blockade leading to an increase in intraocular pressure and vision loss. The oculocardiac reflex stimulation (more common than retrobulbar hemorrhage) may lead to bradycardia and heart block but rarely has significant long-term sequelae. Central retinal artery occlusion leads to painless vision loss, while puncture of the posterior globe leads to painful vision loss without an increase in intraocular pressure.

Question 30

Oculocardiac reflex

Answer 30

Pressure or retraction of the eye leads to ciliary and gasserian ganglia stimulation (trigeminal nerve, afferent limb) followed by vagal stimulation (efferent limb). This can cause significant bradycardia, heart block, and even arrest. Many clinicians propose the use of glycopyrrolate or atropine pretreatment prior to retrobulbar block.

Question 31

Management of aspiration

Answer 31

• placing patient in head down or lateral position and initiating supplemental oxygen
• Not all patients necessarily require intubation or positive pressure ventilation.
• Bronchoscopy is recommended prior to positive pressure ventilation for large particles to avoid pushing the aspirates further into the lungs.
• Prophylactic antibiotic treatment is NOT recommended nor are steroids.

Question 32

DEFINE OLIGURIA

Answer 32

In an average adult: Normal urine output is 0.5-1.0 mL/kg/hr. Oliguria is defined as less than 0.5 mL/kg/hr or less than 400 mL per day. Anuria is defined as less than 50 mL per day.

Question 33

Pulsus paradoxus

Answer 33

A decrease >10 mm Hg of systemic blood pressure during INSPIRATION (not expiration) is called pulsus paradoxus and is characteristic of cardiac tamponade.

Question 34

H2 blockers

Answer 34

Cimetidine, ranitidine, and famotidine are common H2 blockers that are used to increase gastric pH. Additionally, they can reduce gastric volumes (except for ranitidine). When given orally these medications have an onset of action of approximately 1 hour.

Question 35

the two disadvantages of autotransfusion

Answer 35

Platelet and clotting factor depletion are disadvantages of autotransfusion via intraoperative blood salvaging.

Question 36

left sided central line with pleuritc chest pain

Answer 36

Thoracic duct injury should be suspected if the patient develops ipsilateral supraclavicular swelling or unilateral (very rarely, bilateral) pleural effusions after left-sided central venous catheterization. The pleural effusion will most likely exhibit as gradually worsening dyspnea and pleuritic chest pain.

Question 37

VOice that tires easly after parathyroid surgery

Answer 37

The incidence of nerve injury following parathyroidectomy is low but it is a significant complication of surgery. The most commonly injured nerve is the superior laryngeal nerve, and because symptoms are subtle the diagnosis may be missed. The superior laryngeal nerve innervates that cricothyroid muscle. The cricothyroid is the only tensor of the vocal cords and is associated with a voice that tires more easily.

Question 38

Stridor and hoarsness after neck surgery

Answer 38

The recurrent laryngeal nerve injury often is associated with hoarseness and breathlessness. Often the patient will develop stridor because the vocal cord assumes a near midline position when the recurrent laryngeal nerve is injured. Injury to the recurrent laryngeal nerve is more obvious than injury to the superior laryngeal nerve on physical exam.

Question 39

LAte onset stridor after parathyroid surgery

Answer 39

Hypocalcemia is a known complication of parathyroidectomy that often occurs at 24 hours after surgery. Hypocalcemia is associated with muscle spasms and can be associated with late onset stridor.

Question 40

Strabissmus + sux

Answer 40

Children with strabismus are 4 times more likely to demonstrate masseter muscle rigidity (MMR) following succinylcholine administration for general anesthesia than children without strabismus.

Question 41

WHy switch out from bupivicaine causal epidural to lidocaine?

Answer 41

Elevations of bupivacaine can cause cardiac dysrhythmias that are resistant to cardiopulmonary resuscitation, and so this drug is typically discontinued after 48 hours. Epidural lidocaine instead is favored due to low-cost, short half-life, predictable analgesic effect, and availability of serum concentration measurements. One study, which was the largest study on neonates undergoing bladder exstrophy, titrated epidural lidocaine infusions to serum concentration and decreased doses as needed.

Question 42

How to diagnsoe OSA

Answer 42

OSA usually has two components – apneas and hypopneas. Apneas are defined as cessation of breathing that lasts longer than ten seconds despite adequate neuromuscular ventilatory effort. Apneas have to occur more than five times an hour to diagnose OSA. Hypopnea is a partial reduction of airflow of more than 50% lasting at least ten seconds and occurring at least 15 times per hour of sleep. For both apneas and hypopneas, a decrease in the oxygen saturation of at least 4% must be seen to be considered clinically significant.
Most centers use a limit of 5 to 10 AHI per hour as “normal”. Mild disease is 5 to 14, moderate disease is 15 to 29 and severe is greater than 30 events per hour.

Question 43

what is dynamic compliance?

Answer 43

Dynamic compliance is determined by the resistance to airflow through the small airways of the lung while static compliance is determined by the ability of the lung to expand in the setting of static positive airway pressure administration. Dynamic compliance can be estimated by examining the difference between the peak pressures and the plateau pressures in a volume-cycled ventilatory mode with an inspiratory hold. Static compliance can be estimated by taking the difference between the plateau pressure and the positive end-expiratory pressure in a similar mode.

Question 44

Side effect to baby in materanl ritordine use

Answer 44

Neonatal hypoglycemia is a side effect of maternal ritodrine administration.

Question 45

What is in the aldrete score?

Answer 45

The modified Aldrete scoring system is used to assess patients for readiness for discharge from Phase I of PACU. The score looks at activity, respiration, circulation, consciousness, and oxygen saturation.

“6-ARCCO2”

Question 46

Types of errors

Answer 46

Type 1 (I) or α error = incorrectly accepting Ha (false positive)
Type 2 (II) or β error = incorrectly accepting Ho (false negative)

Question 47

What are the hallmarks of HHS?

Answer 47

Hyperosmolar hyperglycemic state is characterized by severe hyperglycemia, severe hyperosmolarity, and severe dehydration. Treatment begins with crystalloid resuscitation.

Question 48

Whart are the effects of ketamine

Answer 48

Ketamine increases HR, BP, CO, CBF, ICP, CMRO2, IOP, salivation, and lacrimation. It preserves respiratory drive, airway reflexes, and acts as a bronchial smooth muscle relaxant. Asthmatic patients can greatly benefit from intravenous ketamine unless contraindications are present (e.g., coronary artery disease (CAD), open globe, increased ICP from intracranial tumor or hemorrhage).

Question 49

MOA SNP

Answer 49

Sodium nitroprusside (SNP) is a direct-acting vasodilator that is converted to nitric oxide in vascular smooth muscle which leads to increased cGMP levels. It is a balanced ARTERIOLAR & VENOUS dilator and therefore decreases both afterload and preload. Nitroprusside has been slowly losing favor owing to its lability in titrating blood pressure, and associated tachyphylaxis and cyanide toxicity when used beyond the acute phase, especially in renal failure patients.

Question 50

WHat is nicardipine?

Answer 50

Nicardipine reduces afterload and blood pressure via arteriolar vasodilation. Given its effect on primarily the arteriolar side, the practitioner’s ability to titrate blood pressure STEADILY is improved compared to using an arterio-venous dilator, such as SNP.

Question 51

Nitro-G MOA

Answer 51

Nitroglycerin is a direct-acting vasodilator by activating vascular cGMP production. It causes greater VENOUS dilation resulting in preload reduction by venous pooling. It also has the added advantage of coronary vasodilation in patients with myocardial ischemia.

Question 52

What is nesteride?

Answer 52

Nesiritide is a recombinant form of human brain natriuretic peptide (BNP) which is normally produced by ventricular myocardium. Brain natriuretic peptide functions as a counter-regulatory hormone to angiotensin II, norepinephrine, and endothelin. Therefore, nesiritide facilitates cardiovascular fluid homeostasis by down-regulating the renin-angiotensin-aldosterone system, suppressing the sympathetic nervous system, suppressing endothelin production, and stimulating cGMP causing arterial AND venous dilation. It does not increase heart rate or inotropy. Its net effects are vasodilation, natriuresis, and diuresis. It has a rapid onset of action and an elimination t1/2 of 15 min

Question 53

What is fenoldapam?

Answer 53

Fenoldopam is a short-acting dopamine type 1 receptor agonist that causes profound peripheral vasodilation via cAMP stimulation with no α or β activity. It is a vasodilator that leads to reductions in preload and afterload, stimulates diuresis and natriuresis, and is useful in stimulating kidney perfusion while simultaneously treating hypertension.

Question 54

digoxina dn hypokalemia

Answer 54

Hypokalemia potentiates the effect and toxicity of digoxin, and potassium should be monitored in patients receiving potassium-losing diuretics such as furosemide.